The United States will turn over two of NATO's major command posts - in Naples, Italy and Norfolk, Virginia - to European officers, a military source told Reuters on Monday.
The move is in keeping with US President Donald Trump's demands that European nations take more responsibility for their own security. His administration has called for the military alliance, long dominated by the United States, to become a "European-led NATO."
The decision comes amid side tensions between the US and Europe over Greenland.
NATO's next military movements
Regarding the following NATO military actions, earlier on Monday, it was announced that NATO is expected to launch a mission in the coming days that could boost its surveillance and military assets in the Arctic, five sources told Reuters.
The move comes following tensions between US President Donald Trump and European allies over Greenland.
A launch of the Arctic Sentry mission could come as early as this week, when the alliance's defense ministers meet in Brussels, according to three European diplomats, a military official and a person familiar with the matter.
Arctic Sentry could involve military exercises, increased surveillance, additional vessels and air assets in the region, including drones, the diplomats said.
However, officials said the mission would likely focus on using NATO resources in the region more effectively rather than adding large amounts of new forces.